Bag-making machine

ABSTRACT

A machine for making bags having cross bottom end closures, comprising an end closure forming station from which each bag moves with the end closure folded over so that an inner half of the end closure lies flat against one side of the bag, a delivery station and, disposed between the stations, a diverter which is controlled by end-closure checking means and is effective to reject faulty moving bags from a conveying path for the bags between the stations, the checking means for said inner half comprising photoelectric reflection sensors cooperating with stationary reflectors for checking any deviation in the position of edges of the inner half from a predetermined desired position as the bags are moved past the checking means, wherein guide means provided in the conveying path for the bags are effective to engage each end closure and erect it to an oblique position so that the said inner half of the end closure is lifted off the said bag side, the reflectors being carried by a bracket disposed such that the reflectors pass between the bag side and the lifted inner half as the bag moves past the checking means.

[ 5] Feb. 22, 1972 [54] BAG-MAKING MACHINE Willi Stork, Apfelallee 3,4542 Techlenburg, Germany Filed: Feb. 11, 1970 Appl. No.: 10,486

[72] lnventor:

[73] Assignee:

[30] Foreign Application Priority Date US. Cl..... ..93/27, 53/53, 93/35SB Int. Cl. ..B3lb l/08, B65b 57/02, B3 lb 29/74 Field of Search..L..93/8, 27, 35 SB; 53/53 [56] References Cited UNITED STATES PATENTSBeert ..53/53 Hennig ..53/53 X Primary Examiner-Wayne A. Morse, Jr.AttarneyFleit, Gipple & Jacobson [57] ABSTRACT A machine for making bagshaving cross bottom end closures, comprising an end closure formingstation from which each bag moves with the end closure folded over sothat an inner half of the end closure lies flat against one side of thebag, a delivery station and, disposed between the stations, a diverterwhich is controlled by end-closure checking means and is effective toreject faulty moving bags from a conveying path for the bags between thestations, the checking means for said inner half comprisingphotoelectric reflection sensors cooperating with stationary reflectorsfor checking any deviation in the position of edges of the inner halffrom a predetermined desired position as the bags are moved past thechecking means, wherein guide means provided in the conveying path forthe bags are effective to engage each end closure and erect it to anoblique position so that the said inner half of the end closure islifted off the said bag side, the reflectors being carried by a bracketdisposed such that the reflectors pass between the bag side and thelifted inner half as the bag moves past the checking means.

11 Claims, 2 Drawing Figures PAIENTEDFEBZZ I972 3,643,552

. FIG-1 355 373 357 INVENTOR Willi STORK AT T RNEYS BAG-MAKING MACHINEThe invention relates to an improvement in or modification of thebagmaking machine forming the subject of prior patent application Ser.No. 684,327 dated Nov. 20, I967, now US. Pat. No. 3,524,389, issued Aug.18, 1970, which concerns a machine for making bags having cross-bottomend closures, comprising an end-closure forming station, a deliverystation and, disposed between them, a diverter which is controlled byend-closure checking means and is effective to reject faulty bags from aconveying path between the stations.

The present invention aims to provide equipment which permits moreefficient checking of the end closures.

According to the invention, a machine for making bags havingcross-bottom end closures comprises an end-closure forming station fromwhich each bag moves with the end closure folded over so that an innerhalf of the end closure lies flat against one side of the bag, adelivery station and, disposed between the stations, a diverter which iscontrolled by endclosure checking means and is effective to rejectfaulty moving bags from a conveying path for the bags between thestations, the checking means for said inner half comprisingphotoelectric reflection sensors cooperating with stationary reflectorsfor checking any deviation in the position of edges of the inner halffrom a predetermined desired position as the bags are moved past thechecking means, wherein guide means provided in the conveying path forthe bags are effective to engage each end closure and erect it to anoblique position so that the said inner half of the end closure islifted off the said bag side, the reflectors being carried by a bracketdisposed such that the reflectors pass between the bag side and thelifted inner half as the bag moves past the checking means. Preferably,the guide means are effective to engage the outer half of each endclosure for the purpose of erecting the entire end closure to an obliqueposition. It is also preferred that the guide means engage the endclosure from above so as to depress the outer half of each end closure,the stiffness that is imparted to each end closure at the formingstation as a result of various folding operations ensuring thatdepression of the outer half will cause the inner half to be lifted.

The guide means preferably comprise one or more rollers turning at thesame speed and in the same direction as the moving bags and eflective toroll on and depress the outer half of each end closure. Compared withstationary guide rails, such rollers have the advantage that they willonly rarely cause displacement of any flaps or labels that werepreviously freshly stuck over the folds of the end closure for thepurpose of reinforcing the latter.

By reason of the different breadths of end closures for various bagsthat are likely to be made by the machine, it is advisable to use aplurality of rollers rather than just one, the rollers then being spacedfrom one another to suit the largest breadth of end closure that may beencountered. Such a set of a plurality of rollers need not be adjustedfor different bag sizes because it is clearly also in a position toengage narrower end closures.

The rollers may have equal diameters and be rotatable on shafts whichare in a staggered arrangement corresponding to the oblique position ofthe end closures, each roller being driven by a belt from a drive shaftthat is common to all the rollers. The advantage of having only a singledrive shaft can, however, be obtained only if all the rollers have thesame diameter.

To permit the oblique position for the end closures to be set, the shaftfor each roller may be carried at an end of a lever, the levers beingindependently pivotable and fixable on a common pivot so as to set thedesired staggered arrangement for the shafts.

In an alternative embodiment, the rollers may be independently rotatableon a common shaft and have different diameters corresponding to theoblique position of the end closures. In this case, the rollers wouldhave to be driven at different speeds, for example by means of a steppeddisc and drive belts, so that the peripheral speed of all the rollers isthe same and equal to the speed of movement of the bags.

For the purpose of maintaining very close tolerances when sensing theedges of the end closures with the aid of photoelectric reflectionsensors, it is desireable that the reflector should underlie the innerhalf of the end closure as closely as possible, irrespective of thebreadth of the end closure. With this aim in mind, the aforementionedbracket preferably carries all the sensors and reflectors for scanningthe inner hall of each end closure and in such a way that the lightbeams are normal to the oblique end closure. Of course the face of thereflector will in this case be parallel to the oblique end closure andit can therefore be brought very closely beneath the end closure. I

In a preferred form of the invention, the bracket is adjustable in adirection parallel to the oblique end closure. In this way the sensorsand reflectors can be set to any desired breadth of end closure withouthaving to make separate adjustments to each sensor and reflector. Thechecking means for the outer half of each end closure may also, comprisephotoelectric reflection sensors and reflectors carried on a commonfurther bracket that is also adjustable in a direction parallel to theoblique end closure. This permits the checking means for the outer halfof the end closure to consist of the same components arranged in mirrorimage to the components of the checking means for the inner half. Bothbrackets may be mounted on a common fixed guide for displacement in adirection parallel to the oblique end closure and adjustable to move inopposite sensors by means of a spindle provided with left-hand andright-hand screw threads. This considerably simplifies adjustment of thechecking means to suit different breadthsof end closures for differentsizes of bags made by the machine.

An example of the invention is illustrated in the accompanyingdiagrammatic drawings, wherein:

FIG. I is a front elevation of end-closure checking means for abagmaking machine, and

FIG. 2 is a plan view of the checking means taken in the direction ofthe arrow A in FIG. 1.

The end-closure checking means for cross-bottom bags comprise means 350in the conveying path of each bag 351 for erecting the end closure 352of the bag from a flat position F F at which an inner half of the endclosure lies on one side of the bag, to an oblique position EE inclined,say, 15 to 20 to the side of the bag. The checking means also compriseequipment 353, including photoelectric reflection sensors 354, 355, 356and 357 cooperating with associated stationary reflectors 358, 359, 360and 361 for detecting any deviation in the position of edges of the endclosure from a predetermined desired position as the bags are moved pastthe sensors in the direction of the arrow 0. The erecting means 350 andthe equipment 353 are arranged downstream (as viewed in relation to thedirection of bag movement) of an end-closure forming station (not shown)and upstream of a delivery station (not shown), the arrangement beingsuch that each bag 351 with its end closure 352 fed along a machinetable 362 will move through under same.

The erecting means 350 comprise a set of rollers 363, 363' which extendsover a distance equivalent to the largest breadth b of end closure thatmay be encountered. Each roller 363, 363 is rotatably mounted at thefree end of a lever 364. All the levers 364 are clamped to a commonshaft 366 fixed to a machine frame 365 and they can be independentlyswung to a desired rotary position and then clamped in this position.The rollers have equal diameters. The shafts on which the rollers rotateand which are carried at the ends of the levers 364 can be staggered ina vertical plane so that, as shown in FIG. 1, all the rollers willcontact an imaginary plane EE which is inclined to the horizontalconveying plane F-F of the bags and which conforms to the obliqueposition to which the end closures of the bags are to be erected. Theplane EE passes through the longitudinal centerline L-L of the endclosure, the inner half of which is on the left-hand side of this centerline and lies on the side of the bag. The roller arrangement is suchthat the group of rollers 363 is on the left-hand side of the centerlineL-L of the end closure of each bag arriving at the checking stationwhile the rollers 363' are located to the right of the centerline. Aseach bag arrives at the checking station. the rollers 363' will depressthe outer half of the end-closure, this outer half projecting beyond andtherefore not being supported by the machine table 362, whereby theentire end closure will be erected to an oblique position in the planeE-E. The rollers 363 guide the inner half of the bag closure as thisinner half is being lifted off the side of the bag.

The rollers 363, 363' are driven by belts 367 from a common drive roller368 of which the shaft 369 is mounted in the machine frame 365 andcoupled to the drive of the entire bag making machine. The peripheralspeed of the. rollers is equal to the conveying speed of the bags and ofcourse their direction of rotation is such that the parts that makecontact with a bag are moving in the same direction as the bag.

The equipment 353 comprises two brackets 370, 371 which support thephotoelectric sensors and associated reflectors. The brackets aredisplaceable towards and away from one another along guide rods 372,373, i.e., parallel to the oblique plane E-E. The guide rods extendacross each end closure and are mounted in the machine frame 365 bymeans of bearing blocks 374. The brackets 370, 371 are locatedsymmetrically with respect to the longitudinal center line LL of the endclosure and are adjustable with respect to the center line by means of aspindle 375 which has a right-hand screw thread 376 and a left-handscrew thread 377 engaging in respective nuts carried by the brackets. Inthis way, rotation of the spindle will cause the brackets to be adjustedin unison but in op posite directions.

The bracket 370 carries the sensors 354 and 355 with associatedreflectors 358 and 359 for scanning the inner half of each end-closure,the sensing beams St being directed normal to the oblique plane E-Econtaining the erected end closure. The reflectors 358, 359 are fixed tolateral flanges of the brackets in the manner indicated in FIG. 1 sothat, as each bag passes the checking station, these flanges will enterthe space between the side of the bag and the inner half of the obliqueend-closure, this causing the sensing beams St to be interrupted. Thesenser 354 is intended to scan the inclined edges 378, 378' of the innerhalf of each end closure while the senser 355 serves to scan the edge379.

The sensors 356, 357 and associated reflectors 360, 361 serve to scanthe edges 380, 380 and 381, respectively, of the outer half of each endclosure. They are carried by the bracket 371 in an arrangement which isa mirror image of that of the corresponding components of the checkingmeans for the inner half of the end closure, thereby providing asymmetrical arrangement with respect to the centerline LL. Thissymmetrical arrangement will not be upset when the brackets 370, 371 areadjusted by turning the spindle 375 to suit a different breadth ofendclosure.

If the end-closure forming station that precedes the illustratedchecking apparatus produces the end closures so that they come tounderlie a side of the bag, it will be clear that the checking apparatuscan be readily modified so that it lies beneath the conveying plane F-Fof the bags.

What is claimed is:

' 1 A machine for making bags having cross-bottom end closures,comprising an end-closure forming station from which each bag moves withthe end closure folded over so that an inner half of the end closurelies flat against one side of the bag, a delivery station and, disposedbetween the stations, a diverter which is controlled by end-closurechecking means and is effective to reject faulty moving bags from aconveying path for the bags between the stations, the checking means forsaid inner half comprising photoelectric reflection sensels cooperatingwith stationary reflectors for checking any deviation is the position ofedges of the inner half from a predetermined desired position as thebags are moved past the checking means, wherein guide means provided inthe conveying path for the bags are effective to engage each end closureand erect it to an oblique position so that the said inner half of theend closure is lifted off the said baglside, the reflectors beingcarried by a bracket disposed suc that the reflectors pass between thebag side and the lifted inner half as the bag moves past the checkingmeans.

2. A machine according to claim 1, wherein said guide means areeffective to engage the outer half of each end closure.

3. A machine according to claim 2, wherein the guide means comprise oneor more rollers turning at the same speed and in the same direction asthe moving bags and effective to roll on and depress the outer half ofeach end closure.

4. A machine according to claim 3, wherein the guide means comprise aplurality of rollers spaced to suit the largest breadth of end closurethat may be encountered.

5. A machine according to claim 4, wherein the rollers have equaldiameters and turn on shafts which are in a staggered arrangementcorresponding to the oblique position of the end closures.

6. A machine according to claim 5, wherein the shaft for each roller iscarried at an end of a lever, the levers being independently pivotableand fixable on a common pivot.

7. A machine according to claim 4, wherein the rollers independentlyturn on a common shaft, have different diameters corresponding to theoblique position of the end closures and are driven at different speedsso that their peripheral speeds are the same and equal to the speed ofmovement of the bags.

8. A machine according to claim 1, wherein the sensors and reflectorsare fixed to a common said bracket so that the light beams are normal tothe oblique end closure.

9. A machine according to claim 8, wherein the bracket is adjustable ina direction parallel to the oblique end closure.

10. A machine according to claim 1, wherein the checking means for theouter half of each end closure also comprise photoelectric reflectionsensors and reflectors carried by a common further bracket that isadjustable in a direction parallel to the oblique end closure.

11. A machine according to claim 10, wherein the bracket carrying thechecking means for the outer half of each end closure and the bracketcarrying the checking means for the inner half of each end closure aremounted on a common fixed guide for displacement in a direction parallelto the oblique end closure and are adjustable to move in opposite sensesby means of a spindle provided with left-hand and right-hand screwthreads.

2. A machine according to claim 1, wherein said guide means areeffective to engage the outer half of each end closure.
 3. A machineaccording to claim 2, wherein the guide means comprise one or morerollers turning at the same speed and in the same direction as themoving bags and effective to roll on and depress the outer half of eachend closure.
 4. A machine according to claim 3, wherein the guide meanscomprise a plurality of rollers spaced to suit the largest breadth ofend closure that may be encountered.
 5. A machine according to claim 4,wherein the rollers have equal diameters and turn on shafts which are ina staggered arrangement corresponding to the oblique position of the endclosures.
 6. A machine according to claim 5, wherein the shaft for eachroller is carried at an end of a lever, the levers being independentlypivotable and fixable on a common pivot.
 7. A machine according to claim4, wherein the rollers independently turn on a common shaft, havedifferent diameters corresponding to the oblique position of the endclosures and are driven at different speeds so that their peripheralspeeds are the same and equal to the speed of movement of the bags.
 8. Amachine according to claim 1, wherein the sensors and reflectors arefixed to a common said bracket so that the light beams are normal to theoblique end closure.
 9. A machine according to claim 8, wherein thebracket is adjustable in a direction parallel to the oblique endclosure.
 10. A machine according to claim 1, wherein the checking meansfor the outer half of each end closure also comprise photoelectricreflection sensors and reflectors carried by a common further bracketthat is adjustable in a direction parallel to the oblique end closure.11. A machine according to claim 10, wherein the bracket carrying thechecking means for the outer half of each end closure and the bracketcarrying the checking means for the inner half of each end closure aremounted on a common fixed guide for displacement in a direction parallelto the oblique end closure and are adjustable to move in opposite sensesby means of a spindle provided with left-hand and right-hand screwthreads.